/*
 '请注意文件编码，如果客户端的md5文件编码和服务器端的md5文件编码不一样，则加密出来的字符串不一样
 '修改:xilou 2080711
 '例子:
       'www.chinacms.org'.MD5();//默认为16位加密
	   'www.chinacms.org'.MD5(32);//32位加密
*/
String.prototype.MD5 = function (bit)
{
	var sMessage = this;
	function RotateLeft(lValue, iShiftBits) { return (lValue<<iShiftBits) | (lValue>>>(32-iShiftBits)); } 
	function AddUnsigned(lX,lY)
	{
		var lX4,lY4,lX8,lY8,lResult;
		lX8 = (lX & 0x80000000);
		lY8 = (lY & 0x80000000);
		lX4 = (lX & 0x40000000);
		lY4 = (lY & 0x40000000);
		lResult = (lX & 0x3FFFFFFF)+(lY & 0x3FFFFFFF); 
		if (lX4 & lY4) return (lResult ^ 0x80000000 ^ lX8 ^ lY8); 
		if (lX4 | lY4)
		{ 
			if (lResult & 0x40000000) return (lResult ^ 0xC0000000 ^ lX8 ^ lY8); 
			else return (lResult ^ 0x40000000 ^ lX8 ^ lY8); 
		} else return (lResult ^ lX8 ^ lY8); 
	} 
	function F(x,y,z) { return (x & y) | ((~x) & z); } 
	function G(x,y,z) { return (x & z) | (y & (~z)); } 
	function H(x,y,z) { return (x ^ y ^ z); } 
	function I(x,y,z) { return (y ^ (x | (~z))); } 
	function FF(a,b,c,d,x,s,ac)
	{ 
		a = AddUnsigned(a, AddUnsigned(AddUnsigned(F(b, c, d), x), ac)); 
		return AddUnsigned(RotateLeft(a, s), b); 
	} 
	function GG(a,b,c,d,x,s,ac)
	{ 
		a = AddUnsigned(a, AddUnsigned(AddUnsigned(G(b, c, d), x), ac)); 
		return AddUnsigned(RotateLeft(a, s), b); 
	} 
	function HH(a,b,c,d,x,s,ac)
	{ 
		a = AddUnsigned(a, AddUnsigned(AddUnsigned(H(b, c, d), x), ac)); 
		return AddUnsigned(RotateLeft(a, s), b); 
	} 
	function II(a,b,c,d,x,s,ac)
	{ 
		a = AddUnsigned(a, AddUnsigned(AddUnsigned(I(b, c, d), x), ac)); 
		return AddUnsigned(RotateLeft(a, s), b); 
	} 
	function ConvertToWordArray(sMessage)
	{ 
		var lWordCount; 
		var lMessageLength = sMessage.length; 
		var lNumberOfWords_temp1=lMessageLength + 8; 
		var lNumberOfWords_temp2=(lNumberOfWords_temp1-(lNumberOfWords_temp1 % 64))/64; 
		var lNumberOfWords = (lNumberOfWords_temp2+1)*16; 
		var lWordArray=Array(lNumberOfWords-1); 
		var lBytePosition = 0; 
		var lByteCount = 0; 
		while ( lByteCount < lMessageLength )
		{ 
			lWordCount = (lByteCount-(lByteCount % 4))/4; 
			lBytePosition = (lByteCount % 4)*8; 
			lWordArray[lWordCount] = (lWordArray[lWordCount] | (sMessage.charCodeAt(lByteCount)<<lBytePosition)); 
			lByteCount++; 
		} 
		lWordCount = (lByteCount-(lByteCount % 4))/4; 
		lBytePosition = (lByteCount % 4)*8; 
		lWordArray[lWordCount] = lWordArray[lWordCount] | (0x80<<lBytePosition); 
		lWordArray[lNumberOfWords-2] = lMessageLength<<3; 
		lWordArray[lNumberOfWords-1] = lMessageLength>>>29; 
		return lWordArray; 
	} 
	function WordToHex(lValue)
	{ 
		var WordToHexValue="",WordToHexValue_temp="",lByte,lCount; 
		for (lCount = 0;lCount<=3;lCount++)
		{ 
			lByte = (lValue>>>(lCount*8)) & 255; 
			WordToHexValue_temp = "0" + lByte.toString(16); 
			WordToHexValue = WordToHexValue + WordToHexValue_temp.substr(WordToHexValue_temp.length-2,2); 
		} 
		return WordToHexValue; 
	} 
	var x=Array(); 
	var k,AA,BB,CC,DD,a,b,c,d 
	var S11=7, S12=12, S13=17, S14=22; 
	var S21=5, S22=9 , S23=14, S24=20; 
	var S31=4, S32=11, S33=16, S34=23; 
	var S41=6, S42=10, S43=15, S44=21; 
	// Steps 1 and 2. Append padding bits and length and convert to words 
	x = ConvertToWordArray(sMessage); 
	// Step 3. Initialise 
	a = 0x67452301; b = 0xEFCDAB89; c = 0x98BADCFE; d = 0x10325476; 
	// Step 4. Process the message in 16-word blocks 
	for (k=0;k<x.length;k+=16)
	{ 
		AA=a; BB=b; CC=c; DD=d; 
		a=FF(a,b,c,d,x[k+0], S11,0xD76AA478); 
		d=FF(d,a,b,c,x[k+1], S12,0xE8C7B756); 
		c=FF(c,d,a,b,x[k+2], S13,0x242070DB); 
		b=FF(b,c,d,a,x[k+3], S14,0xC1BDCEEE); 
		a=FF(a,b,c,d,x[k+4], S11,0xF57C0FAF); 
		d=FF(d,a,b,c,x[k+5], S12,0x4787C62A); 
		c=FF(c,d,a,b,x[k+6], S13,0xA8304613); 
		b=FF(b,c,d,a,x[k+7], S14,0xFD469501); 
		a=FF(a,b,c,d,x[k+8], S11,0x698098D8); 
		d=FF(d,a,b,c,x[k+9], S12,0x8B44F7AF); 
		c=FF(c,d,a,b,x[k+10],S13,0xFFFF5BB1); 
		b=FF(b,c,d,a,x[k+11],S14,0x895CD7BE); 
		a=FF(a,b,c,d,x[k+12],S11,0x6B901122); 
		d=FF(d,a,b,c,x[k+13],S12,0xFD987193); 
		c=FF(c,d,a,b,x[k+14],S13,0xA679438E); 
		b=FF(b,c,d,a,x[k+15],S14,0x49B40821); 
		a=GG(a,b,c,d,x[k+1], S21,0xF61E2562); 
		d=GG(d,a,b,c,x[k+6], S22,0xC040B340); 
		c=GG(c,d,a,b,x[k+11],S23,0x265E5A51); 
		b=GG(b,c,d,a,x[k+0], S24,0xE9B6C7AA); 
		a=GG(a,b,c,d,x[k+5], S21,0xD62F105D); 
		d=GG(d,a,b,c,x[k+10],S22,0x2441453); 
		c=GG(c,d,a,b,x[k+15],S23,0xD8A1E681); 
		b=GG(b,c,d,a,x[k+4], S24,0xE7D3FBC8); 
		a=GG(a,b,c,d,x[k+9], S21,0x21E1CDE6); 
		d=GG(d,a,b,c,x[k+14],S22,0xC33707D6); 
		c=GG(c,d,a,b,x[k+3], S23,0xF4D50D87); 
		b=GG(b,c,d,a,x[k+8], S24,0x455A14ED); 
		a=GG(a,b,c,d,x[k+13],S21,0xA9E3E905); 
		d=GG(d,a,b,c,x[k+2], S22,0xFCEFA3F8); 
		c=GG(c,d,a,b,x[k+7], S23,0x676F02D9); 
		b=GG(b,c,d,a,x[k+12],S24,0x8D2A4C8A); 
		a=HH(a,b,c,d,x[k+5], S31,0xFFFA3942); 
		d=HH(d,a,b,c,x[k+8], S32,0x8771F681); 
		c=HH(c,d,a,b,x[k+11],S33,0x6D9D6122); 
		b=HH(b,c,d,a,x[k+14],S34,0xFDE5380C); 
		a=HH(a,b,c,d,x[k+1], S31,0xA4BEEA44); 
		d=HH(d,a,b,c,x[k+4], S32,0x4BDECFA9); 
		c=HH(c,d,a,b,x[k+7], S33,0xF6BB4B60); 
		b=HH(b,c,d,a,x[k+10],S34,0xBEBFBC70); 
		a=HH(a,b,c,d,x[k+13],S31,0x289B7EC6); 
		d=HH(d,a,b,c,x[k+0], S32,0xEAA127FA); 
		c=HH(c,d,a,b,x[k+3], S33,0xD4EF3085); 
		b=HH(b,c,d,a,x[k+6], S34,0x4881D05); 
		a=HH(a,b,c,d,x[k+9], S31,0xD9D4D039); 
		d=HH(d,a,b,c,x[k+12],S32,0xE6DB99E5); 
		c=HH(c,d,a,b,x[k+15],S33,0x1FA27CF8); 
		b=HH(b,c,d,a,x[k+2], S34,0xC4AC5665); 
		a=II(a,b,c,d,x[k+0], S41,0xF4292244); 
		d=II(d,a,b,c,x[k+7], S42,0x432AFF97); 
		c=II(c,d,a,b,x[k+14],S43,0xAB9423A7); 
		b=II(b,c,d,a,x[k+5], S44,0xFC93A039); 
		a=II(a,b,c,d,x[k+12],S41,0x655B59C3); 
		d=II(d,a,b,c,x[k+3], S42,0x8F0CCC92); 
		c=II(c,d,a,b,x[k+10],S43,0xFFEFF47D); 
		b=II(b,c,d,a,x[k+1], S44,0x85845DD1); 
		a=II(a,b,c,d,x[k+8], S41,0x6FA87E4F); 
		d=II(d,a,b,c,x[k+15],S42,0xFE2CE6E0); 
		c=II(c,d,a,b,x[k+6], S43,0xA3014314); 
		b=II(b,c,d,a,x[k+13],S44,0x4E0811A1); 
		a=II(a,b,c,d,x[k+4], S41,0xF7537E82); 
		d=II(d,a,b,c,x[k+11],S42,0xBD3AF235); 
		c=II(c,d,a,b,x[k+2], S43,0x2AD7D2BB); 
		b=II(b,c,d,a,x[k+9], S44,0xEB86D391); 
		a=AddUnsigned(a,AA); b=AddUnsigned(b,BB); c=AddUnsigned(c,CC); d=AddUnsigned(d,DD); 
	}
	if(bit==32)
	{
		return WordToHex(a)+WordToHex(b)+WordToHex(c)+WordToHex(d);
	}
	else
	{
		return WordToHex(b)+WordToHex(c);
	}
}
